2021/11/01 by Shohini Bhattacharya, Krzysztof Cichy, Bhattacharya, Shohini +9 · 1 citation
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.2111.01056
openalex publication_date 2021/11/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In these proceedings, we summarize the main results from the first-ever calculations of the chiral-even and chiral-odd twist-3 parton distributions, gT(x) and hL(x), of the proton from lattice QCD. We use an Nf=2+1+1 ensemble of maximally twisted mass fermions with a clover improvement. The lattice has a spatial extent of 3~fm, the lattice spacing is 0.093~fm, and the pion mass is 260~MeV. The matrix elements are obtained with a source-sink time separation of 1.12~fm to control contamination from excited states. The calculation is based on the quasi-PDF approach and employs three values for the proton momentum: 0.83~GeV, 1.25~GeV, and 1.67~GeV. The lattice data are renormalized non-perturbatively using the RI' scheme, and the final results are presented in the \rm MS scheme at the scale of 2~GeV. Furthermore, we compute in the same setup the helicity, g1(x), and transversity, h1(x), distributions, which are used to compare gT(x) and hL(x) to their Wandzura-Wilczek approximations. For hL(x), we combine results for the isovector and isoscalar flavor combinations to disentangle the individual up- and down-quark contributions.